A conventional cell sorter which is used for separating, identifying and dispensing a specimen roughly comprises a separating device, a detection device and a dispensing device.
Described below is an explanation of a separating device with reference to FIG. 41. First, a test tube 241 is vibrated or inside of the test tube 241 is stirred in order to unify a condensed specimen 243 in the test tube 241. Then, the condensed specimen 243 in the test tube 241 is repeatedly conducted a process of suction/ejection 251 with a pipette 245. Since the condensed specimen 247 receives a shear stress through the repetition of the suction/ejection 251, the specimen will be separated into single specimen 249. In this manner, a single specimen located at the surface side of the condensed specimen 247 is tend to be subjected to shear stress, which is easily to be separated into the single specimen 249. However, a single specimen located in the center of the condensed specimen 247 is always subjected to high pressure until the separation of the condensed specimen 247 is completed.
Next, described below is an explanation of a detection device with reference to FIG. 42. When a container storing a separated specimen 211 is applied a pressure such as pressurized air 215 in a detection device 201, the specimen 211 flows into a nozzle from its outlet/inlet 214 and goes up through the nozzle. The specimen 211 flew into the outlet/inlet 214 of the nozzle is irradiated by a monitor light 203, and this irradiation generates a fluorescent/scattered light 205. Each specimen is judged by detecting this fluorescent/scattered light 205. At that time, a sample flow 207 including the specimen 211 is surrounded by a sheath flow 209, while the flow speed of the sample flow 207 and the sheath flow 209 are controlled such that the width of sample flow 207 is within a certain range so as to let the specimen 211 flow one by one. This is for the purpose that each specimen is exposed to the monitor light 203.
Described below is an explanation of a dispensing device with reference to FIG. 43. A specimen is dispensed in a dispensing device 221. First, a specimen is applied supersonic vibration in an ejecting device 223 to form liquid droplets. Then, for example, a several hundreds volts of charge is applied to the liquid droplets 225 formed by supersonic vibration.
Then a several hundreds volts of electric pressure is applied through a deflection plate 227 to liquid droplets to dispense it into containers 233,235, while the direction of dropping each liquid drop is separated to a positive pole side 229 and a negative pole side 231. Nonpatent Reference 1: T. Yamashita et al., Cell Technology Vol. 16. No. 10 pp 1532-1541, 1997